1. Technical Field
The present invention relates to a light-emitting device and the manufacturing method thereof, and in particular to a semiconductor light-emitting device and the manufacturing method thereof.
2. Reference to Related Application
This application claims the right of priority based on TW application Ser. No. 94147367, filed Dec. 29, 2005, entitled “Semiconductor Light-emitting Device and Manufacturing Method thereof”, and the contents of which are incorporated herein by reference.
3. Description of the Related Art
Light-emitting diode (LED) devices are widely used in different fields such as displays, traffic lights, data storage apparatus, communication apparatus, lighting apparatus, and medical apparatus. One important task for engineers is to increase the brightness of the LED devices.
In a conventional nitride semiconductor light-emitting device, a structure of the active layer is normally a multiple quantum well (MQW) structure doped with n-type impurities. The quantum well structure includes a well layer sandwiched between each pair of adjacent barrier layers, and there are generally three methods to dope the n-type impurities. The first method is to dope n-type impurities in barrier layers uniformly, and unintentionally dope impurities in well layers. The second method is to dope n-type impurities in well layers uniformly, and unintentionally dope impurities in barrier layers. The third method is to dope n-type impurities in both well layers and barrier layers uniformly. However, the brightness of a light-emitting device manufactured by any of these doping methods is still not satisfactory.
A conventional laser diode includes a quantum well structure comprising a well layer sandwiched between a first barrier layer and a second barrier layer is disclosed to resolve the above problem. The method for manufacturing the laser diode comprises doping impurities at a portion of the first barrier layer at the interface with the well layer while the remaining portion of the first barrier layer is un-doped; doping impurities into a portion of the well layer at the interface with the first barrier layer while the remaining portion of the well layer is un-doped; and doping impurities into a portion of the second barrier layer distant from the interface with the well layer while the remaining portion of the second barrier layer is kept un-doped. Thereby, The brightness of the laser diode is improved.